Isaiah Thomas will be a very tough matchup for the Celtics. (EPA/C.J. Gunther)

The Cleveland Cavaliers have yet to need more than four games to dispatch a playoff opponent in the 2017 NBA playoffs. LeBron James led his team to sweeps against the Indiana Pacers in the first round and then made short work of the Toronto Raptors in the second round, outscoring them by 11 net points per 100 possessions.

If they are going to do the same to Boston, they must prevent the Celtics 5-foot-9 floor general, Isaiah Thomas, from going off like he did against the Washington Wizards.

Thomas scored 27.4 points on 45 percent shooting from the field (25 for 54, 46 percent, from beyond the arc) while dishing out 7.1 assists per game against the Wizards. Almost a third (57 of his 192 points) of his scoring in the series was with John Wall as the primary defender, and Wall is a much tougher defender than Cleveland’s J.R. Smith or Kyrie Irving.

Cavaliers Coach Tyronn Lue told reporters Smith “won’t be on Isaiah [Thomas] to start,” leaving Thomas to Irving when these two teams take the court.

Irving was rated as below-average (bottom 25 percent of the NBA) for his defense against the ballhandler in the pick-and-roll and against spot-up shooters during the regular season and playoffs combined.

Thomas, meanwhile, ranks in the top 10 percent for efficiency in both those offensive categories. As a spot-up shooter he has an effective field goal percentage of 60.6 percent, which rises to 68.3 percent when he goes to his no-dribble jump shot. When he is the ballhandler on the pick-and-roll he is scoring 1.03 points per possession, which rises even higher on passes to the roll man, a spot-up shooter or someone cutting to the basket. Running the pick-and-roll right at Irving would be a recipe for success for the Celtics.

Thomas should also be able to beat Irving one-on-one. In isolation situations, Jeff Teague, Kyle Lowry, Lance Stephenson and Paul George combined to score 17 points off eight possessions in the playoffs, with drives to the left baseline by all opponents yielding a league-high 1.5 points per possession in the regular season and postseason combined. Thomas scored 52 percent of the time going at a defender one-on-one this season, the most of any player with at least 150 isolation possessions.

And when it is time for the big shot, no one is more reliable than Thomas. His 7.7 points per game in clutch situations — the last five minutes of games in which no team is ahead or behind by more than five points — is the most in the postseason and no player contributed more during crucial game situations than Thomas since the regular season started through the postseason, per Mike Beuoy’s clutch win probability added metric.

It’s possible we see James defend Thomas in these late-game situations. James allowed 0.83 points per possession during the regular season as the primary defender (Irving allowed 0.99) and was in the top 10 percent in terms of defending a spot-up shooter (40 percent effective field goal against). But Thomas, despite being small in stature, has shown he won’t wilt when guarded by a larger defender. In fact, during the regular-season meetings against Cleveland, Thomas was 2-for-2 with a foul drawn on spot-up shots against James and 3-for-4 with three drawn fouls as the ballhandler on the pick-and-roll.

“It’s going to be very challenging for us defensively, but it should be,” James told Chris Fedor of Cleveland.com. “It’s the postseason and we wouldn’t want it any other way.”